Aim: Kimmerle's anomaly (ponticulus posticus) is a common anatomical variation of the atlas, is the product of the complete or incomplete ossification of the posterior atlanto-occipital membrane over the vertebral groove, resulting in the formation of a foramen (arcuate foramen) containing vertebral artery and C1 nerve. We aimed to search the variations related to the sulcus arteriae vertebralis which is on the first cervical vertebrae in Turkish population. Material and Method: We retrospectively reviewed 719 3-D CT scanning digital images of consecutive patients between 18-99 years of age with complaints of headache, neck pain, vertigo, tinnitus, hearing loss in relation to the presence of complete or incomplete arcuate foramen. Results: Ponticulus posticus was found unilateral or bilateral in 106(14,7%) patients, bilateral in 48(6,6%), right side alone in 21(2,9%) patients and left side alone in 37(5,1%) patients. We found no statistical significiant difference in symptoms like headache, servical pain, vertigo, tinnitus between the patients with bilateral, unilateral and without arcuate foramen. Discussion: The probability of the presence of arcuate foramen in Turkish population is very high which has to be known in posterior approach.